Coasts case study: Sandbanks, Dorset

Question 1

Where is Sandbanks located?

Answer 1

The South coast of England in Dorset. It separates Poole harbour from Poole bay

Question 2

Why does Sandbanks need management? (2 reasons)

Answer 2

• high number of high value properties and hotels (e.g Sandbanks hotel) which provide employment and generate spending in the local economy
• Residential properties are in high demand and fetch high prices

Question 3

Why does Sandbanks need management? (2 reasons)

Answer 3

• The beach is a major tourist attraction as it has a gentle slope and blue flag status
• Popular for water sports (e.g water skiing, sailing) due to the protection provided by Poole harbour and also houses yacht clubs and marinas which provide money to the local economy

Question 4

Why does Sandbanks need management? (2 reasons)

Answer 4

• The entrance Poole Harbour is used by cross channel ferries and commercial ships (carrying goods such as timber) LSD of the beach could cause the harbour to become clogged
• Climate change means the sea level will rise leaving Sandbanks vulnerable to flooding and could cut the peninsula off from the mainland

Question 5

What is the sea rise likely to be in this area?

Answer 5

0.6m in the next 100 years

Question 6

What is the estimated cost in loss of properties due if no management strategies were applied?

Answer 6

£18m

Question 7

What is the house price of detached houses?

Answer 7

Over £10m

Question 8

What management strategies have been used?

Answer 8

• Wooden groynes

- Beach Recharge

Question 9

How many wooden groynes were constructed?

Answer 9

10

Question 10

How much did each groyne cost?

Answer 10

£100,000

Question 11

How many rock groynes were constructed?

Answer 11

5

Question 12

Why were rock groynes constructed?

Answer 12

• To maintain a wide, deep beach
• To minimise LSD which could otherwise block up the harbour
• They absorb wave energy, which reduced erosion
• More sand means more friction which also reduces wave energy and erosion

Question 13

What is beach recharge?

Answer 13

Offshore sand is sprayed onto the beach

Question 14

How much does beach recharge cost?

Answer 14

£20 per m3

Question 15

Why has beach recharge been used?

Answer 15

Conserves the beach and helps to increase beach size

Question 16

Without groynes what would the rate of erosion be?

Answer 16

1.6m per year

Question 17

i) What is an alternative to the current method of beach recharge?
ii) Why is this beneficial?

Answer 17

i) The dredged sediment is dumped offshore and natural currents will transport this sand onshore
ii) This is much cheaper costing only £3/ m3
Management is working with nature

Question 18

What is the overall strategy for Sandbanks?

Answer 18

Advance the line

Question 19

What benefits to local people/benefits have there been?

Answer 19

Tourism has been protected as the beach is protected

Houses on the edge of the spit have been protected

Question 20

How successful has the management been?

Answer 20

Very successful as:

• The beach has been increasing in size
• The future of the harbour as a port has been protected by interrupting LSD
• Beach recharge has the potential to work well with the natural processes that occur within the beach system
• However there has been increased erosion at Christchurch harbour as LSD has been interrupted